Threading Technology – Clamping Technology 520

475 Thread Gages UNC UNF UNS M MF Rp, R, Rc NPT NPTF STI SELF-LOCK G (BSP) Product Finder Smooth GT, TD Accessories Calibration Tech. Info 6.7 Gaging of other threads 6.7.2.2 Pipe thread for dryseal connections (without sealant) according ANSI B1.20.3 Overview: NPTF PTF-SAE-SHORT NPSF NPSI Each letter in the designation has the following meaning: N National (American) Standard P Pipe T Taper S Straight F Fuel and oil I Intermediate The thread profile is asymmetrical and perpendicular to the thread axle! NPTF thread • Tapered internal thread and external thread Gage system NPTF-1 • Tapered plug gages L 1 with 3 measuring steps (Min., Basis, Max.) • Tapered plug gages L 3 with 3 measuring steps (Min., Basis, Max.) • Tapered ring gages L 1 with 3 measuring steps (Min., Basis, Max.) • Tapered ring gages L 2 with 3 measuring steps (Min., Basis, Max.) Gage system NPTF-2 according to ASME B1.20.5 • Tapered plug gage L 1 with 4 measuring steps • Tapered plug gage L 3 with 4 measuring steps • Tapered smooth plug gage “Crest Check” with 6 measuring steps for minor diameter of nut • Tapered plug gage “Root Check”, thread angle 50°, with 6 measuring steps for major diameter of nut • Tapered ring gage L 1 with 4 measuring steps • Tapered ring gage L 2 with 4 measuring steps • Tapered smooth ring gage “Crest Check” with 6 measuring steps for major diameter of bolt • Tapered ring gage “Root Check”, thread angle 50°, with 6 measuring steps for minor diameter of bolt PTF-SAE-SHORT thread • Tapered internal thread PTF-SAE-SHORT, is coupled with a tapered NPTF external thread • Tapered plug gages L 1 with 3 measuring steps (Min., Basis, Max.) • Tapered plug gages L 3 with 3 measuring steps (Min., Basis, Max.) NPSF thread • Cylindrical internal thread, is screwed with a tapered external thread NPTF • Tapered plug gages L 1 with 3 measuring steps (Min., Basis, Max.) NPSI thread • Cylindrical internal thread, is screwed with a tapered external thread NPTF • Tapered plug gages L 1 with 3 measuring steps (Min., Basis, Max.) 6.7.3 Whitworth Pipe Thread, thread angle 55° 6.7.3.1 Pipe thread for general applications Rp = Cylindrical internal pipe thread (parallel) Rc = Tapered internal pipe thread R = Tapered external pipe thread The thread profile is symmetrical with top and bottom triangles rounded to a circular peak! The thread dimensions of bolt and nut are specified in several national and international standards, e.g.: ISO 7/1 DIN EN ISO 10226-1 DIN EN ISO 10226-2 etc. Internal threads Rp and Rc Gaging is done according to ISO 7/2 resp. DIN EN 10226-3 • Tapered plug gages no. 1 with 1 measuring step (“+”, “–”) for standard screw connections • Tapered plug gages no. 2 with 1 measuring step (“+”, “–”) for checking screw-in depth • Cylindrical check ring gage no. 6 without measuring step for checking gages no. 1 and no. 2 Tapered external thread R Gaging is done according to ISO 7/2 resp. DIN EN 10226-3 • Cylindrical ring gage no. 3 with 1 measuring step (“+”, “–”) • Tapered smooth ring gage no. 4 with measuring step (“+”, “–”) for checking the major diameter of the bolt • Tapered plug gage no. 5 with 1 measuring step for checking gage no. 3 6.7.3.2 Whitworth pipe thread for special screw connections • DIN 3858 = shorter thread lengths • DIN 477, DIN EN 144-1, DIN EN ISO 11363 = gas cylinder valves DIN 3858 Cylindrical internal thread for pipe screw connections with short thread length, is screwed with tapered external thread! • Cylindrical ring gage with 1 measuring step for standard version (tolerance zone position 1) • Cylindrical ring gage with 1 measuring step for short version (tolerance zone position 2) • Cylindrical plug gage GO/NO-GO for checking the Rp internal thread